Two people who, when together, are able to liven up any situation. They manage to make jokes out of every situation, and are highly intelligent.
They use wit, sarcasm, and have impeccable comedic timing.

Most people know a "Duo", and make sure to invite them to all their parties, family gatherings, and social events.

"Hey, did you make sure to invite The Duo to our housewarming on Saturday?"
"Uh, yeah. If we want to make a good impression, we'll need them to keep everyone going."

"I know someone you might click with!"
"You mean, like become a Duo?"

"We have to make sure to see The Duo this summer. Family gatherings are always so boring when they aren't around!"